JGAAP is pretty awesome, it has both Java API and GUI: https://github.com/evllabs/JGAAP https://github.com/evllabs/JGAAP JStylo that was already mentioned is b

JGAAP is pretty awesome, it has both Java API and GUI: https://github.com/evllabs/JGAAP https://github.com/evllabs/JGAAP JStylo that was already mentioned is based on JGAAP. You have some more here: http://evllabs.com/jgaap/w/index.php/FAQ#What_other_tools_are_out_there.3F http://evllabs.com/jgaap/w/index.php/FAQ#What_other_tools_ar...